/*
 * Copyright (c) 2007-2012, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
// OASISXMLCatalogReader.java - Read XML Catalog files

/*
 * Copyright 2001-2004 The Apache Software Foundation or its licensors,
 * as applicable.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.sun.org.apache.xml.internal.resolver.readers;

import java.util.Stack;
import java.util.Vector;
import java.util.Enumeration;
import com.sun.org.apache.xml.internal.resolver.Catalog;
import com.sun.org.apache.xml.internal.resolver.CatalogEntry;
import com.sun.org.apache.xml.internal.resolver.CatalogException;
import com.sun.org.apache.xml.internal.resolver.helpers.PublicId;

import org.xml.sax.*;
import org.w3c.dom.*;

/**
 * Parse OASIS Entity Resolution Technical Committee
 * XML Catalog files.
 *
 * @see Catalog
 *
 * @author Norman Walsh
 * <a href="mailto:Norman.Walsh@Sun.COM">Norman.Walsh@Sun.COM</a>
 *
 */
public class OASISXMLCatalogReader extends SAXCatalogReader implements SAXCatalogParser {
    /** The catalog object needs to be stored by the object so that
     * SAX callbacks can use it.
     */
    protected Catalog catalog = null;

    /** The namespace name of OASIS ERTC catalogs */
    public static final String namespaceName = "urn:oasis:names:tc:entity:xmlns:xml:catalog";

    /** The namespace name of OASIS ERTC TR9401 catalog extension */
    public static final String tr9401NamespaceName = "urn:oasis:names:tc:entity:xmlns:tr9401:catalog";

    protected Stack baseURIStack = new Stack();
    protected Stack overrideStack = new Stack();
    protected Stack namespaceStack = new Stack();

    /** Set the current catalog. */
    public void setCatalog(Catalog catalog) {
        this.catalog = catalog;
        debug = catalog.getCatalogManager().debug;
    }

    /** Get the current catalog. */
    public Catalog getCatalog() {
        return catalog;
    }

    /**
     * Are we in an extension namespace?
     *
     * @return true if the current stack of open namespaces includes
     *               an extension namespace.
     */
    protected boolean inExtensionNamespace() {
        boolean inExtension = false;

        Enumeration elements = namespaceStack.elements();
        while (!inExtension && elements.hasMoreElements()) {
            String ns = (String) elements.nextElement();
            if (ns == null) {
                inExtension = true;
            } else {
                inExtension = (!ns.equals(tr9401NamespaceName) && !ns.equals(namespaceName));
            }
        }

        return inExtension;
    }

    // ----------------------------------------------------------------------
    // Implement the SAX ContentHandler interface

    /** The SAX <code>setDocumentLocator</code> method does nothing. */
    public void setDocumentLocator(Locator locator) {
        return;
    }

    /** The SAX <code>startDocument</code> method does nothing. */
    public void startDocument() throws SAXException {
        baseURIStack.push(catalog.getCurrentBase());
        overrideStack.push(catalog.getDefaultOverride());
        return;
    }

    /** The SAX <code>endDocument</code> method does nothing. */
    public void endDocument() throws SAXException {
        return;
    }

    /**
     * The SAX <code>startElement</code> method recognizes elements
     * from the plain catalog format and instantiates CatalogEntry
     * objects for them.
     *
     * @param namespaceURI The namespace name of the element.
     * @param localName The local name of the element.
     * @param qName The QName of the element.
     * @param atts The list of attributes on the element.
     *
     * @see CatalogEntry
     */
    public void startElement(String namespaceURI, String localName, String qName, Attributes atts) throws SAXException {

        int entryType = -1;
        Vector entryArgs = new Vector();

        namespaceStack.push(namespaceURI);

        boolean inExtension = inExtensionNamespace();

        if (namespaceURI != null && namespaceName.equals(namespaceURI) && !inExtension) {
            // This is an XML Catalog entry

            if (atts.getValue("xml:base") != null) {
                String baseURI = atts.getValue("xml:base");
                entryType = Catalog.BASE;
                entryArgs.add(baseURI);
                baseURIStack.push(baseURI);

                debug.message(4, "xml:base", baseURI);

                try {
                    CatalogEntry ce = new CatalogEntry(entryType, entryArgs);
                    catalog.addEntry(ce);
                } catch (CatalogException cex) {
                    if (cex.getExceptionType() == CatalogException.INVALID_ENTRY_TYPE) {
                        debug.message(1, "Invalid catalog entry type", localName);
                    } else if (cex.getExceptionType() == CatalogException.INVALID_ENTRY) {
                        debug.message(1, "Invalid catalog entry (base)", localName);
                    }
                }

                entryType = -1;
                entryArgs = new Vector();

            } else {
                baseURIStack.push(baseURIStack.peek());
            }

            if ((localName.equals("catalog") || localName.equals("group")) && atts.getValue("prefer") != null) {
                String override = atts.getValue("prefer");

                if (override.equals("public")) {
                    override = "yes";
                } else if (override.equals("system")) {
                    override = "no";
                } else {
                    debug.message(1, "Invalid prefer: must be 'system' or 'public'", localName);
                    override = catalog.getDefaultOverride();
                }

                entryType = Catalog.OVERRIDE;
                entryArgs.add(override);
                overrideStack.push(override);

                debug.message(4, "override", override);

                try {
                    CatalogEntry ce = new CatalogEntry(entryType, entryArgs);
                    catalog.addEntry(ce);
                } catch (CatalogException cex) {
                    if (cex.getExceptionType() == CatalogException.INVALID_ENTRY_TYPE) {
                        debug.message(1, "Invalid catalog entry type", localName);
                    } else if (cex.getExceptionType() == CatalogException.INVALID_ENTRY) {
                        debug.message(1, "Invalid catalog entry (override)", localName);
                    }
                }

                entryType = -1;
                entryArgs = new Vector();

            } else {
                overrideStack.push(overrideStack.peek());
            }

            if (localName.equals("delegatePublic")) {
                if (checkAttributes(atts, "publicIdStartString", "catalog")) {
                    entryType = Catalog.DELEGATE_PUBLIC;
                    entryArgs.add(atts.getValue("publicIdStartString"));
                    entryArgs.add(atts.getValue("catalog"));

                    debug.message(4, "delegatePublic", PublicId.normalize(atts.getValue("publicIdStartString")), atts.getValue("catalog"));
                }
            } else if (localName.equals("delegateSystem")) {
                if (checkAttributes(atts, "systemIdStartString", "catalog")) {
                    entryType = Catalog.DELEGATE_SYSTEM;
                    entryArgs.add(atts.getValue("systemIdStartString"));
                    entryArgs.add(atts.getValue("catalog"));

                    debug.message(4, "delegateSystem", atts.getValue("systemIdStartString"), atts.getValue("catalog"));
                }
            } else if (localName.equals("delegateURI")) {
                if (checkAttributes(atts, "uriStartString", "catalog")) {
                    entryType = Catalog.DELEGATE_URI;
                    entryArgs.add(atts.getValue("uriStartString"));
                    entryArgs.add(atts.getValue("catalog"));

                    debug.message(4, "delegateURI", atts.getValue("uriStartString"), atts.getValue("catalog"));
                }
            } else if (localName.equals("rewriteSystem")) {
                if (checkAttributes(atts, "systemIdStartString", "rewritePrefix")) {
                    entryType = Catalog.REWRITE_SYSTEM;
                    entryArgs.add(atts.getValue("systemIdStartString"));
                    entryArgs.add(atts.getValue("rewritePrefix"));

                    debug.message(4, "rewriteSystem", atts.getValue("systemIdStartString"), atts.getValue("rewritePrefix"));
                }
            } else if (localName.equals("systemSuffix")) {
                if (checkAttributes(atts, "systemIdSuffix", "uri")) {
                    entryType = Catalog.SYSTEM_SUFFIX;
                    entryArgs.add(atts.getValue("systemIdSuffix"));
                    entryArgs.add(atts.getValue("uri"));

                    debug.message(4, "systemSuffix", atts.getValue("systemIdSuffix"), atts.getValue("uri"));
                }
            } else if (localName.equals("rewriteURI")) {
                if (checkAttributes(atts, "uriStartString", "rewritePrefix")) {
                    entryType = Catalog.REWRITE_URI;
                    entryArgs.add(atts.getValue("uriStartString"));
                    entryArgs.add(atts.getValue("rewritePrefix"));

                    debug.message(4, "rewriteURI", atts.getValue("uriStartString"), atts.getValue("rewritePrefix"));
                }
            } else if (localName.equals("uriSuffix")) {
                if (checkAttributes(atts, "uriSuffix", "uri")) {
                    entryType = Catalog.URI_SUFFIX;
                    entryArgs.add(atts.getValue("uriSuffix"));
                    entryArgs.add(atts.getValue("uri"));

                    debug.message(4, "uriSuffix", atts.getValue("uriSuffix"), atts.getValue("uri"));
                }
            } else if (localName.equals("nextCatalog")) {
                if (checkAttributes(atts, "catalog")) {
                    entryType = Catalog.CATALOG;
                    entryArgs.add(atts.getValue("catalog"));

                    debug.message(4, "nextCatalog", atts.getValue("catalog"));
                }
            } else if (localName.equals("public")) {
                if (checkAttributes(atts, "publicId", "uri")) {
                    entryType = Catalog.PUBLIC;
                    entryArgs.add(atts.getValue("publicId"));
                    entryArgs.add(atts.getValue("uri"));

                    debug.message(4, "public", PublicId.normalize(atts.getValue("publicId")), atts.getValue("uri"));
                }
            } else if (localName.equals("system")) {
                if (checkAttributes(atts, "systemId", "uri")) {
                    entryType = Catalog.SYSTEM;
                    entryArgs.add(atts.getValue("systemId"));
                    entryArgs.add(atts.getValue("uri"));

                    debug.message(4, "system", atts.getValue("systemId"), atts.getValue("uri"));
                }
            } else if (localName.equals("uri")) {
                if (checkAttributes(atts, "name", "uri")) {
                    entryType = Catalog.URI;
                    entryArgs.add(atts.getValue("name"));
                    entryArgs.add(atts.getValue("uri"));

                    debug.message(4, "uri", atts.getValue("name"), atts.getValue("uri"));
                }
            } else if (localName.equals("catalog")) {
                // nop, start of catalog
            } else if (localName.equals("group")) {
                // nop, a group
            } else {
                // This is equivalent to an invalid catalog entry type
                debug.message(1, "Invalid catalog entry type", localName);
            }

            if (entryType >= 0) {
                try {
                    CatalogEntry ce = new CatalogEntry(entryType, entryArgs);
                    catalog.addEntry(ce);
                } catch (CatalogException cex) {
                    if (cex.getExceptionType() == CatalogException.INVALID_ENTRY_TYPE) {
                        debug.message(1, "Invalid catalog entry type", localName);
                    } else if (cex.getExceptionType() == CatalogException.INVALID_ENTRY) {
                        debug.message(1, "Invalid catalog entry", localName);
                    }
                }
            }
        }

        if (namespaceURI != null && tr9401NamespaceName.equals(namespaceURI) && !inExtension) {
            // This is a TR9401 Catalog entry

            if (atts.getValue("xml:base") != null) {
                String baseURI = atts.getValue("xml:base");
                entryType = Catalog.BASE;
                entryArgs.add(baseURI);
                baseURIStack.push(baseURI);

                debug.message(4, "xml:base", baseURI);

                try {
                    CatalogEntry ce = new CatalogEntry(entryType, entryArgs);
                    catalog.addEntry(ce);
                } catch (CatalogException cex) {
                    if (cex.getExceptionType() == CatalogException.INVALID_ENTRY_TYPE) {
                        debug.message(1, "Invalid catalog entry type", localName);
                    } else if (cex.getExceptionType() == CatalogException.INVALID_ENTRY) {
                        debug.message(1, "Invalid catalog entry (base)", localName);
                    }
                }

                entryType = -1;
                entryArgs = new Vector();

            } else {
                baseURIStack.push(baseURIStack.peek());
            }

            if (localName.equals("doctype")) {
                entryType = catalog.DOCTYPE;
                entryArgs.add(atts.getValue("name"));
                entryArgs.add(atts.getValue("uri"));
            } else if (localName.equals("document")) {
                entryType = catalog.DOCUMENT;
                entryArgs.add(atts.getValue("uri"));
            } else if (localName.equals("dtddecl")) {
                entryType = catalog.DTDDECL;
                entryArgs.add(atts.getValue("publicId"));
                entryArgs.add(atts.getValue("uri"));
            } else if (localName.equals("entity")) {
                entryType = Catalog.ENTITY;
                entryArgs.add(atts.getValue("name"));
                entryArgs.add(atts.getValue("uri"));
            } else if (localName.equals("linktype")) {
                entryType = Catalog.LINKTYPE;
                entryArgs.add(atts.getValue("name"));
                entryArgs.add(atts.getValue("uri"));
            } else if (localName.equals("notation")) {
                entryType = Catalog.NOTATION;
                entryArgs.add(atts.getValue("name"));
                entryArgs.add(atts.getValue("uri"));
            } else if (localName.equals("sgmldecl")) {
                entryType = Catalog.SGMLDECL;
                entryArgs.add(atts.getValue("uri"));
            } else {
                // This is equivalent to an invalid catalog entry type
                debug.message(1, "Invalid catalog entry type", localName);
            }

            if (entryType >= 0) {
                try {
                    CatalogEntry ce = new CatalogEntry(entryType, entryArgs);
                    catalog.addEntry(ce);
                } catch (CatalogException cex) {
                    if (cex.getExceptionType() == CatalogException.INVALID_ENTRY_TYPE) {
                        debug.message(1, "Invalid catalog entry type", localName);
                    } else if (cex.getExceptionType() == CatalogException.INVALID_ENTRY) {
                        debug.message(1, "Invalid catalog entry", localName);
                    }
                }
            }
        }
    }

    public boolean checkAttributes(Attributes atts, String attName) {
        if (atts.getValue(attName) == null) {
            debug.message(1, "Error: required attribute " + attName + " missing.");
            return false;
        } else {
            return true;
        }
    }

    public boolean checkAttributes(Attributes atts, String attName1, String attName2) {
        return checkAttributes(atts, attName1) && checkAttributes(atts, attName2);
    }

    /** The SAX <code>endElement</code> method does nothing. */
    public void endElement(String namespaceURI, String localName, String qName) throws SAXException {

        int entryType = -1;
        Vector entryArgs = new Vector();

        boolean inExtension = inExtensionNamespace();

        if (namespaceURI != null && !inExtension && (namespaceName.equals(namespaceURI) || tr9401NamespaceName.equals(namespaceURI))) {

            String popURI = (String) baseURIStack.pop();
            String baseURI = (String) baseURIStack.peek();

            if (!baseURI.equals(popURI)) {
                entryType = catalog.BASE;
                entryArgs.add(baseURI);

                debug.message(4, "(reset) xml:base", baseURI);

                try {
                    CatalogEntry ce = new CatalogEntry(entryType, entryArgs);
                    catalog.addEntry(ce);
                } catch (CatalogException cex) {
                    if (cex.getExceptionType() == CatalogException.INVALID_ENTRY_TYPE) {
                        debug.message(1, "Invalid catalog entry type", localName);
                    } else if (cex.getExceptionType() == CatalogException.INVALID_ENTRY) {
                        debug.message(1, "Invalid catalog entry (rbase)", localName);
                    }
                }
            }
        }

        if (namespaceURI != null && namespaceName.equals(namespaceURI) && !inExtension) {
            if (localName.equals("catalog") || localName.equals("group")) {
                String popOverride = (String) overrideStack.pop();
                String override = (String) overrideStack.peek();

                if (!override.equals(popOverride)) {
                    entryType = catalog.OVERRIDE;
                    entryArgs.add(override);
                    overrideStack.push(override);

                    debug.message(4, "(reset) override", override);

                    try {
                        CatalogEntry ce = new CatalogEntry(entryType, entryArgs);
                        catalog.addEntry(ce);
                    } catch (CatalogException cex) {
                        if (cex.getExceptionType() == CatalogException.INVALID_ENTRY_TYPE) {
                            debug.message(1, "Invalid catalog entry type", localName);
                        } else if (cex.getExceptionType() == CatalogException.INVALID_ENTRY) {
                            debug.message(1, "Invalid catalog entry (roverride)", localName);
                        }
                    }
                }
            }
        }

        namespaceStack.pop();

        return;
    }

    /** The SAX <code>characters</code> method does nothing. */
    public void characters(char ch[], int start, int length) throws SAXException {
        return;
    }

    /** The SAX <code>ignorableWhitespace</code> method does nothing. */
    public void ignorableWhitespace(char ch[], int start, int length) throws SAXException {
        return;
    }

    /** The SAX <code>processingInstruction</code> method does nothing. */
    public void processingInstruction(String target, String data) throws SAXException {
        return;
    }

    /** The SAX <code>skippedEntity</code> method does nothing. */
    public void skippedEntity(String name) throws SAXException {
        return;
    }

    /** The SAX <code>startPrefixMapping</code> method does nothing. */
    public void startPrefixMapping(String prefix, String uri) throws SAXException {
        return;
    }

    /** The SAX <code>endPrefixMapping</code> method does nothing. */
    public void endPrefixMapping(String prefix) throws SAXException {
        return;
    }

}
